Thermal Stability of Sugarcane Bagasse Derivatives bearing Carboxyl Groups Synthesized in Ionic Liquid

Abstract

To illuminate changes in the thermal stability of lignocellulosic biomass by homogeneous chemical modification in ionic liquids, sugarcane bagasse derivatives bearing carboxyl groups were prepared in ionic liquids. Fourier transform infrared (FT-IR) spectroscopy and solid-state nuclear magnetic resonance (NMR) confirmed the chemical structure of the derivatives. Sugarcane bagasse derivatives with degree of substituted OH as high as 9.93 mmol/g were achieved. The homogeneous esterification was demonstrated to be a more efficient approach than heterogeneous ones. Based on thermogravimetric analysis, the onset degradation temperature of sugarcane bagasse decreased dramatically to 185 °C, 160 °C and 140 °C, using succinic anhydride, maleic anhydride, and phthalic anhydride as reagent, respectively. A first-order degradation kinetic model was applied to obtain the degradation activation energies of sugarcane bagasse. The results showed that homogeneous chemical modification significantly decreased the thermal stability of sugarcane bagasse by reducing the onset degradation temperature and degradation activation energies.

Recent Progress on Starch Maleate/Polylactic Acid Blends for Compostable Food Packaging Applications

“…Polar ionic liquids (ILs), on the other hand, must have a low melting temperature and viscosity to be considered useful for commercial starch maleate processing. In this respect, imidazolium-based ILs, like 1-butyl-3-methylimidazolium ([C 4 mim]­Cl, viscosity: 11,000 mPa s at 30 °C) and 1-allyl-3-methylimidazolium chloride ([Amim]­Cl, viscosity: 685 mPa s at 30 °C) were identified to be ideal for high-DS maleate synthesis for most biopolymers; ,− however, for starch maleate processing, [C 4 mim]­Cl has been frequently used instead of [Amim]­Cl. The preference is based on a theoretical assumption that [C 4 mim]Cl with a high net basicity , (Figure A) and low cation–anion strength , could provide abundant Cl – anions (Figure B–I) to disrupt H-bonds in starch (in the order of C 6 –OH > C 3 –OH > C 2 –OH of AGU) for high MA substitutions .…”

Pretreated Sugarcane Bagasse Result in More Efficient Degradation by Streptomyces sp S2

“…Some possible explanation are sugarcane bagasse have high lignin enthalpy (around 130 kJ/mol), this makes sugarcane have high lignin thermal stability. This makes bagasse lignin harder to extracted using hydrogen-peroxide within same temperature, compared to biomass that have lower lignin thermal stability (Watkins et al 2015;Chen et al 2016). Another possible explanation is due to acid nature of peroxide treatment, lignin was moved to the surface of bagasse (Xu et al 2017).…”